ATKR Atkore Inc

CUSIP No. 047649 10 8

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CUSIP No. 047649 10 8

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CUSIP No. 047649 10 8

Atkore International Group Inc. (the “Issuer”)

16100 South Lathrop Avenue

Harvey, Illinois 60426

(708) 339-1610

CD&R Allied Holdings, L.P.

CD&R Associates VIII, Ltd.

CD&R Associates VIII, L.P.

CD&R Investment Associates VIII, Ltd.

CD&R Allied Holdings, L.P., CD&R Associates VIII, Ltd., CD&R Associates VIII, L.P. and CD&R Investment Associates VIII, Ltd., have entered into a Joint Filing Agreement, dated May 21, 2018, a copy of which is filed with this Schedule 13G as Exhibit 99.1, pursuant to which such reporting persons have agreed to file this statement jointly in accordance with the provisions of 13d-1(k)(1) under the Securities Exchange Act of 1934.

CD&R Allied Holdings, L.P.

P.O. Box 309, Ugland House, South Church Street,

George Town, Grand Cayman, KY1-1104

Citizenship: Cayman Islands

CD&R Associates VIII, Ltd.

P.O. Box 309, Ugland House, South Church Street,

George Town, Grand Cayman, KY1-1104

Citizenship: Cayman Islands

CD&R Associates VIII, L.P.

P.O. Box 309, Ugland House, South Church Street,

George Town, Grand Cayman, KY1-1104

Citizenship: Cayman Islands

CD&R Investment Associates VIII, Ltd.

P.O. Box 309, Ugland House, South Church Street,

George Town, Grand Cayman, KY1-1104

Citizenship: Cayman Islands

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See Item 2(b) above.

Common Stock, par value $0.01 per share

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(a) [    ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);

(b) [    ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c) [    ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d) [    ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8);

(e) [    ] An investment adviser in accordance with §240.13d-1(b) (1)(ii)(E);

(f) [    ] An employee benefit plan or endowment fund in accordance with §240.13d-1(b) (1)(ii)(F);

(g) [    ] A parent holding company or control person in accordance with §240.13d-1(b) (1)(ii)(G);

(h) [    ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) [    ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) [    ] A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J);

(k) [    ] Group, in accordance with § 240.13d-1(b)(1)(ii)(K).

Not Applicable.

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a) Amount beneficially owned:

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As of the date listed in the table below, each of the Reporting Persons beneficially owned the number and percentage of issued and outstanding shares of common stock of Atkore International Group Inc. listed opposite its name:

(a) Based on 46,577,795 shares of common stock, as of April 27, 2018 as reported on the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on May 8, 2018.

(b) CD&R Allied Holdings, L.P. is a Cayman Islands exempted limited partnership of which CD&R Associates VIII, Ltd. is the general partner, whose sole stockholder is CD&R Associates VIII, L.P., of which CD&R Investment Associates VIII, Ltd. is the general partner. Each of CD&R Associates VIII, Ltd., CD&R Associates VIII, L.P. and CD&R Investment Associates VIII, Ltd. (the “CD&R Affiliates”) expressly disclaims beneficial ownership of the shares held by CD&R Allied Holdings, L.P.

Investment and voting decisions with respect to shares held by CD&R Allied Holdings, L.P. are made by an investment committee of limited partners of CD&R Associates VIII, L.P. (the “Investment Committee”). The CD&R investment professionals who have effective voting control of the Investment Committee are Michael G. Babiarz, Vindi Banga, James G. Berges, John C. Compton, Kevin J. Conway, Russell P. Fradin, Thomas C. Franco, Kenneth A. Giuriceo, Donald J. Gogel, Jillian Griffiths, Marco Herbst, Sarah Kim, John Krenicki, Jr., David A. Novak, Paul S. Pressler, Christian Rochat, Eric Rouzier, Ravi Sachdev, Steven W. Shapiro, Richard J. Schnall, Nathan K. Sleeper, Derek Strum, David H. Wasserman and J.L. Zrebiec. All members of the Investment Committee disclaim beneficial ownership of the shares shown as beneficially owned by the funds associated with Clayton, Dubilier & Rice, LLC.

0% ^*

(i) Sole power to vote or to direct the vote:

0

(ii) Shared power to vote or to direct the vote:

0

(iii) Sole power to dispose or to direct the disposition:

0

(iv) Shared power to dispose or to direct the disposition:

0

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If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [X]:

This Amendment No. 2 to the Schedule 13G is being filed because, as a result of the sale of shares on May 21, 2018, the Reporting Persons no longer hold or beneficially own any shares of common stock of Atkore International Group Inc.

Not Applicable.

Not Applicable.

Not Applicable.

Not Applicable.

Not applicable.

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Signatures

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: May 21, 2018

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